Portable hazardous waste pallet structure
BACKGROUND OF THE INVENTION 
     The present relates to an improved portable pallet structure, and more particularly, to a unique and novel pallet structure capable of accommodating and firmly supporting heavy containers, particularly those carrying hazardous materials from which flow such liquids or small particulates. 
     Various types of pallet structures are known in the art for supporting heavy material containers, such pallet structures including accommodating passages for the insertion of liftingforks to allow the pallet structures to be moved from one location to another. For the most part these past pallet structures have been comparatively complex in manufacture and assembly and have failed to accommodate adequately for container spill, particularly in those situations where the containers are filled with hazardous and/or corrosive materials. Where the prior art does accomplish this purpose, it does so only with expensive constructions. 
     The present invention, recognizing the need to provide an economical to manufacture and assemble pallet structure which accommodates for material spill and yet which is readily accessible for movement of heavy containers to be supported on the pallet structure, provides such a unique and novel pallet structure which fulfills such recognized needs and which at the same time can be manufactured and assembled in an economical manner with a minimum of materials and manufacturing steps. The pallet structure of the present invention not only accommodates for spill of flowable materials from containers, but accommodates for such materials even if they are hazardously corrosive, the inventive structure being capable of stably supporting heavy containers filled with flowable materials, particularly those of a hazardous nature, the novel structure having a large fill capacity for spilled materials, which spilled materials can be distributed uniformly in a confined container space when spilled in large quantities. Further, the novel structure of the present invention provides for multiple fork lift entry in a low profile arrangement which can be readily loaded and unloaded and which can readily incorporate supplemental support structure for the container support platform when needed. 
     Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure herein. 
     SUMMARY OF THE INVENTION 
     More particularly, the present invention provides a portable pallet structure for material carrying containers including: confined chamber means defined by bottom and side wall members with the side wall members extending in a generally vertical direction from the bottom wall member, said side wall members being shaped to provide a plurality of access passages separate from the confined chamber means to permit insertion of pallet lifting means; and, pervious container support platform means mounted in cooperative relation with the side wall members and in spaced relation above the bottom wall member whereby flowable materials spilled from containers supported thereby are collected in the confined chamber means. In addition, the present invention provides a novel support structure for the pervious container support platform including a removable supplemental platform support as well as novel arrangements for utilizing such platform and supplemental supports to direct spill flow in a selected manner. 
     It is to be understood that various changes can be made by one skilled in the art in one or more of the several parts of the novel pallet structure disclosed without departing from the scope or spirit of the present invention. For example, the general pallet structure could be circular rather than rectangular and include more or fewer confined subchambers than as disclosed. Further, the pervious support platform could be an appropriately apertured, foraminous plate with funnel shaped, flow directing apertures and supported in a different manner from the disclosed internal ledge, for example, a plurality of supplemental supports. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings which disclose one advantageous embodiment of the invention: 
     FIG. 1 is an isometric view of the novel portable pallet structure supporting material carrying containers in the form of four cylindrical drums; 
     FIG. 2 is a top plan view of the pallet structure of FIG. 1 with the support platform partially broken away to better illustrate the internal support ledge therefor. 
     FIG. 3 is a cross-sectional view of the pallet structure of FIG. 2, taken in a plane through line 3--3 of FIG. 2; and, 
     FIG. 4 is a cross-sectional view of the pallet structure of FIG. 2, taken in a plane through line 4--4 of FIG. 2. 
    
    
     DETAILED DESCRIPTION OF THE DRAWING 
     As can be seen in FIG. 1 of the drawings, the novel portable pallet structure 2 is disclosed as supporting a plurality of containers or drums 3 suitable for filling with any one of a number of materials to be stored, including liquids and granular materials, some of which can be of a hazardous nature. Pallet structure 2 includes an integral bottom of bottom wall members 4 and side wall members 6 advantageously formed as an integral unit from a suitable corrosion-resistant polyethylene material with the side wall members extending in a generally vertical direction from the bottom wall members 4. These bottom and side wall members are shaped to define a confined chamber 7 which is of rectangular shape in the disclosed embodiment of the invention and includes a plurality of spaced rows of confined subchambers 8 with rows of access passages 9 extending therebetween in crossing relation separate from the spaced subchambers 8. This arrangement permits insertion of pallet lifting means, such as a lift fork (not shown) from any one or more of the sides of the confined chamber 7, thus permitting multiple lift entry. It is to be noted that the outer of the side wall members 6 extends upwardly beyond the defined subchambers 8 to further define an upper rectangular peripheral skirt 11, providing an upper common chamber portion 12 (FIGS. 2-4) which extends over and in communication with spaced subchambers 8. 
     As also can be seen in FIGS. 2-4, upper peripheral skirt 11 is formed or shaped to include a peripherally extending internal support edge or lip 13 which serves to support the peripheral edge of a grating serving as a pervious container support platform 14. 
     Pervious container support platform 14 or grating can be formed from a suitable corrosion-resistant fiberglass material to include a first set of spaced bars 16 of I-shaped cross-section (FIG. 3) and a second set of spaced bars 17 of circular cross-section (FIG. 4) crossing in normal relation to and interconnected with the set of bars 16. Although not shown in detail in the drawings, these bars, like the base portions of I-shaped cross-sectional bars 16 and the downwardly and oppositely sloping upper portions of circular cross-sectional bars 17, can be contoured or shaped in other words to selectively direct any spilled material from containers 3 to flow through the upper spaced bars 16 and 17 into the common chamber portion 12 to the confined subchambers 8 in a more uniform manner, platform or grating 14 being sized so that the peripheral edges thereof rest on the internal support ledge 13 of peripheral skirt 11. 
     As also can be seen in FIGS. 2-4 of the drawings, a removable supplementary or secondary support can be provided for the pervious container support platform 14. Advantageously, this secondary support can be formed from a suitable corrosion-resistant polyvinyl material as a cylindrical container or tube 18 sized to be removably disposed within the central subchamber of the nine subchambers 8 disclosed as serving to provide the plurality of spaced rows of confined subchambers. Tube 18 includes a ring of spaced apertures 19 along the upper portion thereof so as to allow spilled materials therein to flow to the surrounding subchamber and or subchambers 8. It is to be noted that tube 18 is positioned and sized in both height and breadth to provide an undersupport for platform or grating 14. That is to say, platform 14 spans a relatively short free distance in any longitudinal direction before it meets some form of undersupport. This is an important feature of my invention, because it enables the entire structure to be lighter in weight than constructions which require or have longer free spans before meeting the undersupport. In this regard, it is further to be noted that although only one such supplementary or secondary support container 18 is disclosed, it would be possible to use a plurality of such containers, depending upon the number of subchambers included in the pallet and/or the nature of the load to be supported by platform or grating 14. 
     From the above description, it can be seen that a unique and novel low profile, readily loadable and unloadable pallet structure is provided which is comparatively straightforward and economical in manufacture and assembly, which can be adapted to handle varying loads of flowing material, particularly those of a hazardous nature, with a minimum of waste loss and a minimum of sloshing in the event of a spill.